Ocean acidification is predicted to intensify in the coming decades, and is likely to disrupt physiological processes and have far-reaching consequences for marine habitats, organisms and ecosystems. Ocean acidification and warming have synergistic effects that exacerbate the risk of population declines in sensitive species.  Combined with rising temperatures, sea-level rise and more frequent and higher magnitude/amplitude extreme events, ocean acidification threatens the goods and services provided by ecosystems. Further targeted research is important to understand the impact of ocean acidification on marine living resources. Consideration of acidification trajectories and biotic impacts will be essential for predicting futures and planning conservation efforts in the Southern Ocean region.

Climate change and its impacts are of much concern globally and to the Antarctic Treaty System given realised and expected impacts on global sea level rise and biodiversity.

The recent Special and Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC) provide the clearest current summaries of global climate change that has taken place, impacts that are being realised, and changes that are forecast.

Attention is drawn here to key findings from these IPCC Reports, focussing on substantial uncertainties about global, Antarctic and Southern Ocean impacts; and to the research being undertaken through SCAR to address these uncertainties.  The paper presented here is not intended as a comprehensive synthesis.

Key uncertainties include the current and future behaviour of the Antarctic cryosphere (notably implications for global sea level and coastal populations and infrastructure); climatic variability over short timescales which is especially important given its significance for impacts and operational forecasts; and the future of Antarctic marine biodiversity, approaches to improve its conservation, and ways to mitigate climate change impacts on both.

Quantifying and reducing these uncertainties through focussed research is critical.

More critical is the need to convey to nations the importance of the Paris Climate Agreement, and expected strengthening of greenhouse gas emissions reductions targets, for maintaining Antarctic and Southern Ocean environments and their biodiversity.

The incidental mortality of seabirds in longline and trawl fisheries continues to be a serious global concern, especially for threatened albatrosses and petrels. The need for international cooperation in addressing this concern was a major reason for establishing the Agreement on the Conservation of Albatrosses and Petrels (ACAP). There are currently 31 species listed in Annex 1 of the Agreement. Of the 22 species of albatrosses, 12 breed or forage in the Convention Area, as do four of the nine listed petrel species. This paper provides a summary of the status and current trends of these 16 species as well as an update on ACAP resources relevant to seabird bycatch mitigation in trawl and demersal longline fisheries.

The Catch Documentation Scheme for Dissostichus spp. (CDS) was effectively implemented in 2020 by 17 Member States, 3 Acceding States, 1 non-Contracting Party (NCP) cooperating with CCAMLR by participating in the CDS and 1 one NCP with limited access to the CDS. CDS reports of catches outside the Convention Area have decreased from 2019 to 2020. The Secretariat contacted 12 NCPs to seek their engagement in the CDS in 2021.

Analysis of the trends in the CDS data for 2019 and 2020 has identified decreases in the number of Dissostichus Catch Documents (DCDs), Dissostichus Export Documents (DEDs), and Dissostichus Re-Export Documents (DREDs) between these years, thought to be a result of the global COVID-19 pandemic. Across both years, France landed the largest quantity of toothfish (5 632 tonnes and 5 623 tonnes respectively) and exported the largest quantity of toothfish (4 487 tonnes and 3 596 tonnes respectively). The largest quantity of imports was by the United States of America (USA) in both years followed by China.

Oceanites, Inc. is a US-based, nonprofit, scientific, and educational organization under U.S. law, which was founded in 1987 (https://oceanites.org). Its mission is to advance science-based conservation and to increase the awareness of climate change, its potential impacts, and climate change adaptation through the lens of Antarctic penguins.

This report summarizes activities of Oceanites since CCAMLR-39 and SC-CAMLR-39, including:

• Update on the Antarctic Site Inventory

• Update on the Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD) database

• MAPPPD Related Projects

• State Of Antarctic Penguins Report and Penguin Population Changes

• Update on Climate Change

This paper summarises data collected by Scheme of International Scientific Observation observers and vessels, of incidental interactions between fishing vessels, seabirds and marine mammals during fishing activities undertaken during the 2020 and 2021 seasons. The extrapolated total of 44 seabirds caught in 2020 is the lowest on record for CCAMLR fisheries. Three humpback whales were recorded as incidental mortalities in krill fisheries in 2021, the first mortality records for this species.